Search Publications
Multiwavelength Spectroscopy of the Bipolar Outflow from Cepheus E
Smith, Michael D.; Eislöffel, Jochen; Froebrich, Dirk
Cepheus E is the site of an exceptional example of a protostellar outflow with a very young dynamical age and extremely high near-infrared luminosity. We combine molecular spectroscopic data from the submillimeter to the near-infrared in order to interpret the rotational excitation of CO and the rovibrational excitation of H2. We conclu…
Low Coronal Signatures of Large Solar Energetic Particle Events
Nitta, Nariaki V.; Tylka, Allan J.; Cliver, Edward W.
We report on the low coronal signatures of major solar energetic particle (SEP) events. Because large SEP events are highly associated with both flares and coronal mass ejections, we focused on flare-associated motions in soft X-rays. In a sample of a half-dozen well-observed flares associated with SEP events, we identified two basic types of moti…
Elemental Abundances in NGC 3516
Turner, T. J.; Kraemer, S. B.; George, I. M. +2 more
We present Reflection Grating Spectrometer data from an XMM-Newton observation of the Seyfert 1 galaxy NGC 3516, taken while the continuum source was in an extremely low flux state. This observation offers a rare opportunity for a detailed study of emission from a Seyfert 1 galaxy, as these are usually dominated by high nuclear continuum levels an…
Ultraviolet-Optical Pixel Maps of Face-on Spiral Galaxies: Clues for Dynamics and Star Formation Histories
Conselice, Christopher J.; de Grijs, Richard; Windhorst, Rogier A. +8 more
Ultraviolet and optical images of the face-on spiral galaxies NGC 6753 and NGC 6782 reveal regions of strong ongoing star formation that are associated with structures traced by the old stellar populations. We use these images to construct NUV-(NUV-I814) pixel color-magnitude diagrams (pCMDs) that reveal plumes of pixels with strongly v…
The Gravitational Lens B1608+656. I. V-, I-, and H-Band Hubble Space Telescope Imaging
Blandford, R. D.; Surpi, G.
We present a multiwavelength analysis of high-resolution observations of the quadruple lens B1608+656 from the Hubble Space Telescope archive, acquired with WFPC2 through filters F606W (V band) and F814W (I band) and with NIC1 in filter F160W (H band). In the three bands, the observations show extended emission from the four images of the source i…
The Quintuple Quasar: Radio and Optical Observations
Keeton, Charles R.; Winn, Joshua N.; Kochanek, Christopher S. +1 more
We present results from high-resolution radio and optical observations of PMN J0134-0931, a gravitational lens with a unique radio morphology and an extremely red optical counterpart. Our data support the theory of Keeton & Winn: five of the six observed radio components are multiple images of a single quasar, produced by a pair of lens galaxi…
Hα Impact Polarization Observed in a Gradual Flare
Hanaoka, Y.
Linear polarization of the Hα line was detected in kernels of a gradual flare, which was accompanied by a filament eruption. The maximum degree of polarization of this flare exceeds 1%, and the orientation of the polarization is approximately perpendicular to the flare ribbons. These results can be explained with the assumption that the observed p…
Hubble Space Telescope STIS Spectroscopy of the White Dwarfs in the Ultrashort-Period Dwarf Novae VY Aquarii and WX Ceti
Szkody, Paula; Howell, Steve B.; Sion, Edward M. +2 more
We present the results of a multicomponent synthetic spectral analysis of Hubble Space Telescope (HST) STIS spectra of the ultrashort-period dwarf novae VY Aqr and WX Ceti during their deep quiescence following their last superoutburst. The white dwarf in these extremely low accretion rate systems dominates the far-UV light. We find that the accre…
Spectroscopic Identification of White Dwarfs in the New Luyten Two-Tenths Survey
Vennes, Stéphane; Kawka, Adela
We spectroscopically identify New Luyten Two-Tenths (NLTT) stars from the reduced proper-motion diagram of Salim & Gould. Five out of 16 objects investigated are identified as white dwarfs: four hydrogen-rich DA stars (NLTT 8581, NLTT 31748, NLTT 53177, and NLTT 56805) and one helium-rich (NLTT 8435). The properties of the stars are further co…
Detection of Far-Infrared Features in Star-Forming Regions
Onaka, Takashi; Okada, Yoko
We report the detection of a feature at 65 µm and a broad feature around 100 µm in the far-infrared spectra of the diffuse emission from two active star-forming regions, the Carina Nebula and Sharpless 171. The features are seen in the spectra over a wide area of the observed regions, indicating that the carriers are fairly ubiquitous …